Conventional, buckle-type, paper sheet folding machines typically employ two sheet-receiving chutes or pockets and at least four cooperating rollers. The rollers define an arrangement of three pairs of coacting rollers through which a sheet is sequentially fed so as to convey the sheet into and out of the pockets to create two folds. Typical designs are disclosed in U.S. Pat. Nos. 2,751,221, 4,573,672, and 4,834,699.
While conventional paper folding machines may function generally satisfactorily, such machines must be properly operated and maintained. On occasion, a paper sheet may jam in a folding machine, and this can result from a number of factors. For example, the paper sheet may have had a pre-existing tear or the paper sheet may have been inserted or fed in an improper manner. In any event, the "jam" must be cleared. Typically, conventional machines require that the entrance pair of rollers be manually turned or cranked in a direction opposite to the normal rotation direction so as to "back out" the jammed paper.
In extreme cases, portions of the machine housing or some of the internal components may have to be removed by a technician to provide access to an interior part of the machine to permit removal of the jammed paper. Thus, it would be desirable to provide an improved roller system that would accommodate the more rapid and efficient clearing of paper jams.
In some cases, a conventional machine must be partially disassembled and the sheet-receiving pocket or pockets removed to facilitate clearing of the jammed paper. It would be advantageous to provide an improved design which would accommodate removal of some of the rollers to afford access to the pockets for jammed paper retrieval without requiring removal of the pockets. Such an improved system should preferably require only relatively simple operations which could be readily understood and performed by an ordinary office worker.
As a paper folding machine is used, particles of paper, as well as other dirt particles, may be deposited on the entrance rollers--especially on a knurled metal roller which is typically employed as one of the two rollers defining the entrance roller pair. Eventually the build up of such particulate matter must be removed to insure optimal machine performance. Accordingly, it would be desirable to provide an improved system for accommodating the cleaning of such rollers.
Also, over time, the operation of a paper folding machine results in wear of the components. Typically, one of the rollers of the entrance roller pair functions as a central roller which contacts the other three rollers. This central roller is typically fabricated from a resilient, rubber or elastomeric material. This roller, being relatively soft, can wear more quickly and is more likely to be damaged during operation.
For example, when a multi-sheet, stapled letter is folded in the folding machines, the staple is pressed against the resilient material of the roller as the sheets pass through the nip of the entrance roller pair. The metal staple tends to be impressed into the resilient material of the rubber or elastomeric roller and cause a temporary deformation or indentation in the material. This subjects the material to a greater, localized pressure. Over time, the repeated pressure from staples can lead to the degradation of the surface finish of the material.
Also, occasionally a staple is not properly closed, and a sharp end of the staple may dig into the resilient material and tear or gouge the surface of the material. Eventually, the roller becomes so worn or damaged that the operation of the machine is deleteriously affected. It then becomes necessary or desirable to replace the resilient roller.
In many conventional paper folding machines, roller replacement is a somewhat involved task and may require the services of a technician. This, of course, usually requires scheduling of the service and shut down of the machine until it has been serviced and placed back into operation.
The repair, maintenance, and/or replacement of paper folding machine rollers causes undesirable inefficiencies and disruption of office work. The inventor of the present invention has recognized that it would be desirable to provide an improved roller mounting design which could facilitate maintenance and replacement of rollers by an ordinary office worker so that it would not be necessary to call in a trained technician.
Thus, it would be particularly beneficial if such an improved design could permit the complete removal of one or more rollers by the ordinary office worker in a simple and quick manner so as to facilitate removal of old rollers and installation of new rollers.
It would also be desirable to provide an improved mounting system for rollers in a manner that provides clear and easy access to the rollers for cleaning, as well as for facilitating removal and reinstallation. Preferably, such an improved system should permit removal, cleaning, and replacement of one or more rollers (e.g., an entrance roller pair) by the ordinary office worker without disassembly of other machine components and without the use of tools.
It would also be advantageous to provide an improved roller pair system which could accommodate different paper thicknesses as well as multiple sheets of paper.
Further, it would be desirable to provide such an improved roller system with a design that could accommodate incorporation of the system in a relatively small machine. In particular, it would be advantageous to provide the system with a configuration and size that could be accommodated in a relatively small, table top machine for use on an office desk or table.
Finally, it would also be beneficial if such an improved roller system in a small, paper folding apparatus could be incorporated in other paper-handling office machines such as xerographic machines. For example, the present invention contemplates employing an improved, small, paper folder apparatus at the output end of a xerographic machine for providing the user with folded copies. Preferably, such an improved paper folder apparatus in a xerographic machine would readily accommodate roller access, cleaning, removal, and replacement in a quick and simple manner by the ordinary office worker.
The present invention provides, among other things, an improved roller mounting system which can accommodate designs having the above-discussed benefits and features.